[MEncoder-users] Generating switchable binary subtitles with MEncoder

[Giacomo Comes]

On Mon, Oct 29, 2007 at 06:53:54PM +0200, Francois Visagie wrote:
> On 10/29/07, Nicolas George <nicolas.george at normalesup.org> wrote:
> > L'octidi 8 brumaire, an CCXVI, Giacomo Comes a écrit:
> > > spumux (part of dvdauthor) is able to convert text subtitles to spu format
> > > since forever. After uou have them in spu format you can extract them to
> > > vobsub format if you like.
> >
> > I mentioned spumux, but I also mentioned that it does not handle font
> > subtleties: you can not have italic, for example.
> 
> Also, the whole reason I hoped to turn to MEncoder for encoding binary
> subtitles was because I got turned off spumux (I am actually using
> dvdauthor for authoring). The reasons in my case were 1) unless you
> provide it with SSA subtitles, it adjusts the timing with no way of
> disabling that behaviour (and I'm recreating DV DATECODE display which
> depends on perfectly adjacent subtitles to prevent flashing) and

Can you clarify what you mean with "it adjusts the timing"?
What spumux does that you want to disable?

> 2) it doesn't do anti-aliasing. In fact it only seems to use text and border
> colours, possibly in addition to background which is transparent of
> course.

The code in spumux that render text subtitles in graphic subtitles
comes from mplayer. So basically both should do the same work.
About anti-aliasing, what I know is that it requires a lot of colors.
ImageMagick when it renders a one color text with anti-aliasing can use 
up to 256 different colors. The rendering looks very nice, but then
if you put it in a DVD subtitle you cannot have more that 4
colors in total. How do you keep the anti-alias effect if you can only
use 1 or may be 2 colors for the text and 1 or 2 for the border?
I suspect that MPlayer use anti-alias and it looks nice because when 
it displays the subtitle on screen it can use as many colors as it needs.

But I may be totally wrong on this as I'm not an anti-alias expert.
If what I'm saying is incorrect I hope somebody else can correct me.

Giacomo

> So I'm looking for a way of generating high-quality anti-aliased
> binary subtitles for muxing in as switchable subtitles outside of
> dvdauthor, and I had hoped it was possible to dump binary subtitles
> generated by MEncoder into a file. They are so beautiful... I know
> there are hosts of Windows subtitle utilities around, all with their
> different input and output formats and abilities and idiosyncrasies to
> learn, what a schlep...
> 
> Regards,
> Francois